Chemical sensors which are lightweight, portable, and inexpensive are needed for anti-terrorism and environmental applications. Magnetoresistive sensors have found applications in magnetic data storage as well as in automotive and other process control sensing applications. However, converting chemical sensing into a magnetically detectable signal has not been reported. The ability to detect environmental contaminants through low-voltage, battery or solar-powered magnetoresistive sensors would be a major breakthrough in deploying such sensors in a variety of areas, as opposed to optical chemical sensing which requires both an optical source such as a laser (often intense for laser-induced breakdown spectroscopy) and a detector.
As such, a need exists for a low-voltage, battery or solar-powered magnetoresistive sensor having the ability to detect environmental contaminants.